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reaction

/rɪˈækʃən/
noun★Intermediate
general

A response to a stimulus, event, or situation, often involving physical, emotional, or cognitive changes.

The patient's reaction to the medication was severe.

Her reaction to the news was one of shock and disbelief.

💡

Can refer to chemical, biological, or psychological responses.

technical

In chemistry, a process in which substances interact to form new substances.

The reaction between sodium and chlorine produces table salt.

The chemical reaction was exothermic, releasing heat.

💡

Often involves reactants and products.

Collocations

reaction timeThe time it takes to respond to a stimulus.chain reactionA self-sustaining series of reactions.reactionaryOpposed to change or innovation.

Synonyms

Antonyms

Related Phrases

knee-jerk reactionidiom
An immediate, unthinking response.
nuclear reactionphrase
A reaction involving atomic nuclei.

💡Pro Tip

Context Matters

The meaning of 'reaction' varies by context—ensure you use it appropriately in scientific, emotional, or general discussions.

⚡Gold Rule

Scientific vs. General Use

In science, 'reaction' refers to chemical processes; in everyday language, it describes responses to events or stimuli.

📖Word Origin

From Middle French 'réaction,' from Latin 'reactio,' meaning 'a going back,' from 'reagere' (to act against).

📝Usage Notes

In everyday language, 'reaction' often refers to emotional or behavioral responses. In science, it describes chemical or physical processes.

Word Breakdown

re-
back, again
prefix
+
-act
to do, act
root
+
-ion
the act of
suffix
English Dictionary

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